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Thursday, September 1, 2011

The fresh taste of tomatoes, just off the vine and still warm from the sun... is there any taste that says summer better? This is the vegetable we long for most when supermarkets offer rather flavorless winter tomatoes from south of the border.

Tomato processing procedures have changed over the past several years. You now need to process tomatoes by adding citric acid or lemon juice to each pint or quart.

Questions & Answers about TomatoesQ. How can I tell if the tomatoes I can are high acid?A. You really can’t tell so treat all tomatoes as a low acid product.

Q. Why do I have to acidify tomatoes when canning them? A. Red tomatoes all use to be high acid. Not so anymore. Adding bottled lemon juice, or citric acid ensures that tomatoes have enough acid to be safely processed in a water bath canner.

Q. How much lemon juice or citric acid should I add to pints or quarts?A. To ensure safe acidity in whole crushed or juiced tomatoes, add two tablespoons of bottled lemon juice or ½ teaspoon of citric acid per quart of tomatoes. For pints, use one tablespoon bottled lemon juice or 1/4 teaspoon citric acid.

Q. I like to add celery, green pepper, and onions to tomatoes when I can them. Is this safe?A. Adding other vegetables lowers the acidity of tomatoes, which can provide a favorable environment for the growth of botulism bacteria. This product would require the pressure canner method of processing and use of reliable directions.

Q. Sometimes, after opening one of my jars of home-canned ketchup, I notice a white substance on the inside of the lid. It’s not soft and fuzzy like mold, but seems rather hard and granular. The lid is still sealed before the jar is opened. Can I use my ketchup?A. Yes. The white substance you describe is calcium acetate, which is formed when the acid in the food and the calcium carbonate in the sealing composition of the lid come in contact with one another. It sometimes forms on the lids of high acid foods such as ketchup, chili sauce or other tomato products. The formation of calcium acetate crystals is harmless. It’s easy to tell the difference between the two: mold is soft and slimy, while crystals of calcium acetate are hard and granular to the touch.